According to the Washington Post, the National Highway Traffic Safety Administration has released a fresh report that links as many as 89 deaths and 57 injuries to Toyota’s known unintended acceleration problems.

This count points only to the cases which have occurred within the last decade – from 2000 through mid-May 2010 – the same period that also saw over 6,200 complaints of Toyota’s demonstrating unintended acceleration filed with the safety organization. This new report shows a substantial increase from the previous number suggested – 52 deaths – which may also pose a greater legal challenge for the automaker as it faces an onslaught of lawsuits.

Toyota pointed to the lacking information accompanying complaints filed with NHTSA for the discrepancy in the death count, saying that it is still working with law enforcement to determine the causes of accidents.

“For any manufacturer, lack sufficient detail that could help identify the cause of an accident. We will continue to work in close partnership with law enforcement agencies and federal regulators with jurisdiction over accident scenes whenever requested,” said Toyota in a statement.

Toyota vehicles in unintended acceleration crashes may be linked to 89 deaths since 2000, up from 52 reported in March, the National Highway Traffic Safety Administration said.

The deaths occurred in 71 crashes, more than the 43 reported in March, the agency said Tuesday, citing data through May 20, in an e-mailed response to Bloomberg News.

The agency has received 6,200 complaints concerning sudden, unintended acceleration in Toyota vehicles from 2000 to mid-May, the agency said, up from 2,600 in March.

U.S. regulators haven't found evidence to warrant a new defect investigation after speaking to 100 car owners who complained about sudden acceleration after Toyota recalled and repaired their vehicles, NHTSA Administrator David Strickland said at a Thursday House hearing.

Toyota hasn't found any electronics flaws after examining more than 2,000 vehicles that would help explain sudden acceleration, Toyota Motor Sales USA President James Lentz said at the hearing.

Toyota has said it will install advanced brake-override systems in all new models beginning in 2011. The company will also retrofit seven current models with a software fix, which slows a vehicle if it receives signals both to accelerate and brake, Lentz told a House committee in February.

The Transportation Department said May 18 that Toyota had paid a record $16.4-million U.S. fine for failing to alert regulators quickly enough about defects that could cause unintended acceleration.